The invention relates to a device comprising semiconductor elements and elements of an oxidic material, electrically conductive connections being provided between the semiconductor elements and the oxidic elements, the electrically conductive connections comprising at least one antidiffusion layer. If desired, the electrically conductive connection may be formed exclusively by the antidiffusion layer.
The invention also relates to a method of manufacturing such a device.
As oxidic elements there can be used, for example: conductor tracks of an oxidic superconducting material and dielectric elements of a ceramic material such as titanates and zirconates, for example barium titanate.
In an article by M. Gurvitch and A. T. Fiory in Applied Physics Letters 51 (13), pages 1027 to 1029 (1987), a description is given of a method for the patterned manufacture of thin films of the superconducting compound YBa.sub.2 Cu.sub.3 O.sub.7 on various substrates, inter alia, silicon. In practice it was found that most substrates require an antidiffusion layer. For this purpose, not only electrically insulating layers but also electrically conductive antidiffusion layers were investigated such as layers of Ag, Nb and Cu, but this did not lead to the desired result on silicon substrates because the layers adhered poorly and the oxidic compound did not exhibit superconducting behaviour at the desired temperatures (above 77 K.).
Substrates on which oxidic superconducting materials can be satisfactorily provided are in general insulating oxidic materials such as MgO, ZrO.sub.2 and SrTiO.sub.3, and noble metals such as gold and silver. Gold and silver can be used to form electrically conductive connections, but they do not form an effective diffusion barrier. Moreover, because of the possible formation of a Si-Au eutectic composition at a low temperature gold is less suitable for use in contact with semiconductor devices. Silver, too, is less suitable for this purpose because of the high diffusion rate of silver.
Antidiffusion layers for use in semiconductor devices must meet a number of requirements. In semiconductor technology, for example, protective layers of Si.sub.3 N.sub.4 are used which are applied at a temperature of 450.degree. C. At this temperature there must be no undesired reactions in and between the previously applied layers. Nor must there be oxidation of the antidiffusion layers at this temperature.